アクティブボード・２０１５年１０月
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研究発表を行った学会；
・第88回日本細菌学会総会
　２０１５年　３月２６日〜２８日（長良川国際会議場、岐阜）
タイトル；Protein S-guanylation occurring in Escherichia coli and its association with growth condition.
発表者；津々木　博康　氏
　　　（熊本大学　大学院生命科学研究部　微生物学分野）
要旨；
8-Nitroguanosine 3’, 5’-cyclic monophosphate (8-nitro-cGMP) is a nitrated cGMP derivative formed in mammals. It can act as a second messenger for reactive oxygen species and nitric oxide via a post-translational modification (PTM) of protein thiols through cGMP adduction (protein S-guanylation). Recently, we identified the endogenous formation of 8-nitro-cGMP in Salmonella enterica serovar Typhimurium (unpublished data), suggesting the notion that it may also act as a signaling molecule in bacteria. We here investigated the occurrence of protein S-guanylation in Escherichia coli (E. coli). Protein S-guanylation was studied by means of Western blotting with the use of anti-S-guanylation antibody. In 1-D electrophoresis, several bands were clearly observed in lysates of E. coli, suggesting that multiple proteins were susceptible for protein S-guanylation. Interestingly, those protein bands were more intensed when E. coli were cultured under static condition than shaking condition. After 2-D electrophoresis, S-guanylated protein spots were subjected to proteomic analysis. Several protein spots were successfully identified, including GroEL, DnaK and enolase. These data suggest that protein S-guanylation is a physiological PTM in E. coli, and it could be regulated by environmental factors such as oxygen supply. Further study is warranted to clarify its signaling role in bacteria.